The crash happened on the London-bound carriageway of the A2 just before the junction for Dartford Heath at around 8.08am this morning (Friday).
It involved a grey BMW motorbike and a black Kawasaki motorbike.
Police and ambulance crews were called and a man aged in his 30s died at the scene.
His next of kin have been informed.
A second man was taken to hospital in London with serious injuries.
Enquiries are being carried out by the Kent Police Serious Collision Investigation Unit.
Motorists who were in the area are urged to check for any dashcam footage, which may assist the investigation.
Footage can be uploaded via online portal – https://kep.uk.evidence.com/axon/community-request/public/ryjg046 and witnesses can also provide information by contacting Kent Police on 01622 798538 and quoting reference RY/JG/046/24, or by emailing sciu.td@kent.pnn.police.uk.
